Need some info about a seeming dinosaur

[william antley]

Got to work on a system that may be as old as I am for the last couple of days. I would like to get some information about it if anyone can help me. There are no service manuals, wiring diagrams or any other type of literature about this particular system I have been working with.

It's a WESTINGHOUSE system, OD unit was:
Model S1090A1R, May be S1090AIR
Style 354A339G13
Serial H02947

The AHU is a WESTINGHOUSE
Model AC030A2M1
Style 352A782G08
Serial FRO 0966

It's controlled by a MASTERTROL MARK XXXI for three zones, each using the TMT thermostat to work the damper motor and control the OD unit.

I had to replace the OD unit due to excessive refrigerant leakage from various components in the unit. Stuff that could never be repaired. Mostly the shell of what I believe is a heat exchanger and around a sub-cooling valve mounted in the liquid line.

I was given a TRANE TTA090A400FA unit to replace it and had a lot of trouble getting it to work properly due to a complete lack of knowledge of the control system. I've managed to get the system to operate for cooling but, it ain't pretty and I don't know if heat will still operate as it should. Whoever installed this control system used a lot of the same color wires with minimal identification on any of the wiring and there are no diagrams whatsoever of how the controls are wired. I spent the better part of the day just tracing the conduits out to locate the components of the system. I still don't know where much of the wiring is or how it is configured.

Mostly my curiosity is about the WESTINGHOUSE OD unit. What type of unit is it? I'm reasonably certain it is straight AC as I could not find any reversing valve in it to show it's a heat pump. If it was a AC only unit, it was pretty tricked out from the factory for what I think is a high efficiency operation.

Any info at all will be greatly appreciated. If you ahve knowledge of the MASTERTROL system, that would be a bonus to me! Many thanks to you all!!

[twcpipes]

Found eight articles by typing in "Mastertrol" in search. Aol took me to Google for it. I can't bring in the link to the page showing them for some reason.

[william antley]

Thanks twcpipes! I completely forgot about using a search engine, must be working too hard or something. I appreciate the input!

[twcpipes]

Cool, glad to help
tom

[Chillermec]

I assume its an S"T"090 unit, rather than S1090. That would be a 7 1/2 ton condensing unit with can compressor. Seems that I recall the compressors had unloading capability. It is possible I can lay hands on an old I&M that was scanned into a pdf file. I'll check and see if it was scanned to send to you.

[Chillermec]

I do have two files on CD that I think will help you, although I don't have an 090' listed in them. Is the Trane unit 90 tons? Or 7 1/2 tons? Either way I'm sure the files will help you out. How can I send them to you??

[william antley]

My unit is a 7.5 ton, or it was. I had to replace it with a new 7.5 ton CU. There are 3 others of this make and model on the customers site so, I probably need to learn about them. I think the ones remaining are 10 ton but, I didn't look to closely 'cause I wasn't working with them.
Can you e-mail the files to me? I'm pretty sure my e-mail addy is in my profile. I'm gonna check to make sure and put it there if it isn't.
If that's not an option, let me know how you can send them and I'll work with you. I appreciate your help more than you know!!
Since I did that change-out, I'm probably going to be the "go-to" tech for that site.
I'm not sure if that's a good thing or a bad thing.

You're probably right about the unit model number, it was not in the most readable shape and had been scratched on a few times in a feeble attempt to read it. Of course, building maintenance having painted over it in the past didn't help.
I rubbed over it with a black marker and rubbed off the top layer of ink leaving some in the letter recesses. It still wasn't very readable but, it was a little better.

[Edited by william antley on 07-17-2004 at 09:46 PM]